After a blowout party at a secluded island cabin, five friends make a shocking discovery: a dead body and the only boat off the island gone. Trapped and unable to call for help, they become prey to a mysterious killer seeking revenge. Together, they must decipher the murderer's chilling series of clues to reveal the island's secret past ... or face death one by one.

James Murphey is a rugged cryptozoologist, who thirty years earlier, during a trip to Loch Ness, Scotland, had a fatal encounter with the fabled "Nessie" creature that killed his father, and left James with deep facial scar. Twenty years later, James is hunting for Nessie, when his search leads him to the sleepy town of Pike Island, Ashburn, on Lake Superior. Hiring Josh Riley as his guide, James and Josh bond over their mutual scientific interests and deceased fathers, while James tries to convince Josh's mother, Sheriff Karen Riley, that the 60-foot plesiosaur is killing and breeding.